Marigold Leaves Turning Purple? (7 Causes + FIX)

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Are your Marigold Leaves turning Purple? Don’t worry. We have some tips to help you with this problem. Marigolds are a common flower in gardens and are a popular bedding plant. They feature an appealing warm color and perfectly synced foliage.

They also complete their entire life cycle in a single growing season. Their blooms vary in size and construction, but regardless of their color, you will find one that suits your style.

The most common cause for marigold leaves turning purple is a lack of phosphorus, which is vital for flower development. This nutrient is often depleted in the soil, so a simple fertilizer that contains phosphorus will be a great solution.

Well, let’s look first at the most common cause and solution below and

Marigold Leaves Turning Purple? (Causes + FIX)

Use this guide to determine the root of the problem and return your plants to their original health.

Phosphorus deficiency

A phosphate (P) is vital for the growth of roots. If there’s a shortage of phosphorus in the soil, or the plant is having difficulty absorbing it, the leaves will change from dark green to slightly purple. Without intervention, the plants may be stunted in growth and have delayed flowering. In addition, the leaves may be blotchy and curled.

Give the plant food a dose of bone meal or superphosphate and cover the soil with organic mulch to help warm the soil and resolve the issue.


The powdery mildew type of fungus creates white mold in marigold flower petals. The marigold flowers will gradually transform into purple because of the fungus.

Spores may become airborne and spread to different plants within your yard. Over-watering and fertilizing with nitrogen can also promote the growth of fungal spores.

Plants should be spread away from each other to ensure sufficient air circulation. In the case of extreme circumstances, additional treatment may be needed. Apply a fungicide to your plants in spring before the appearance of powdery mildew. Then, as required, apply the fungicide all through the entire year.

Mix one tablespoon of baking soda into a quarter of water for an easy solution. Spray the plants heavily. The solution should only kill the fungus it comes into contact with.

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Mold infection

The usual cause of mold is the fungus Sclerotinia. The name implies that it creates a white, downy mold on the damaged stems and leaves. Other signs are the leaves becoming wilted and dry or brittle within the affected area.

Sclerotia are tiny rigid, black, and hard-to-see structures that can develop on the stems of plants that have been infected. The marigold flowers can become purple as a result.

Mold spores can remain in the garden for as long as five years. Therefore, eliminating it from the garden can be a challenging task. In addition, in humid, ideal conditions, the spores multiply into fungi which release more spores.

This disease is incurable and untreatable. So, all affected marigold plants must be removed from your garden.

Make sure that new plants have plenty of room. When you transplant them, do this to allow for ventilation and to keep the foliage dry. Limit the quantity of moisture. The humidity should be between 30 and 50%. You could use a humidifier to control the moisture.

Potassium deficiency

Potassium (K) is essential for vigorous growth. In addition, it is vital in producing sugars and starches to enhance flower production.

It’s also essential in the process plant cells use to produce food. Chlorophyll, found in plant cells, aids in absorbing sunlight energy in photosynthesis. As a result, the plant converts carbon dioxide and water into carbohydrates and oxygen stored and used to create new leaves and plant components.

Potassium is vital for this photosynthesis process. Therefore, a lack of potassium causes weakly formed plants that may cause their leaves to turn violet.

To solve the issue, fertilize the marigold using a nutrient with high potassium. Fertilizers that are based on seaweed or algae are high in potassium. So are the products made from wood ash or granite dust.

Magnesium deficiency

Magnesium (Mg) is located in plants’ core of chlorophyll cells. It is also vital as potassium is for photosynthesis. Without magnesium, it causes chlorophyll deficiencies, slowed and weak plant growth, and even purple leaves.

Organic compost is an excellent mineral source. Ensure you frequently add organic compost to your soil, mix in, or use it as mulch.

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It is also possible to add magnesium as magnesium sulfate, also known as Epsom salt.

The dose recommended for one plant is one tablespoon of Epsom salts in half gallon water for each foot the plant’s height. Spray the solution onto the leaves of plants every two weeks, and the plants should be back to normal.

Cold ground

Marigold seeds have difficulty absorbing essential minerals like potassium and phosphorus from soils that are too cold. As a result, the leaves could become yellow or purple until the soil begins to warm up.

The issue can be resolved when the soil gets warmer, and the leaves return to their original green. However, the plant’s growth could be affected by the deformation or stunting of its growth. The plant may not also produce enough buds to ensure a successful fruit crop.

Plant seeds when the soil is warm later in the season to prevent this issue.


Seedlings exposed to excessive sunlight or close to growing light sources can be afflicted with sunburn. In addition, the leaves can change to red or purple and then curl up and crisp if not taken care of.

Change the light source to the seedlings, and apply a general fertilizer if required. Also, do in-depth research on what other causes turn your marigold leaves purple.

See Also: Why Is My Cilantro Turning Yellow? (How to Fix)


Building a lovely and colorful landscape with plants like marigolds is possible without needing to be cautious in their maintenance. With enough water, they can live in typical soil at warm temps.

However, if you notice that your leaves turn purple, it signifies something is amiss with your plant. To boost your plant’s health and avoid purple leaves, keep an eye on temperatures and soil quality.

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